Collaborative Research: EAGER--Effect of Eddy Forcing Induced by Eyewall and Rainband Convection on Tropical Cyclone Rapid Intensification

该研究旨在提高我们对控制热带气旋（TC）增强的内部动力学的理解，并提高TC强度快速变化的预报技巧。该项目的结果和产品可以立即在TC预测的业务模型中实施，传播到更广泛的TC建模社区，并用于首席研究员（PI）的TC理论和应用课程教学。该项目支持一名博士后研究员。 该项目的教育目标是培养和教育下一代的科学家与博士后研究人员和研究生/本科生的参与。热带气旋（TC）强化的传统观点将绝对角动量视为摩擦层上方的一个物质守恒量。 本研究试图证明与眼壁和雨带对流相关的涡动过程是方位平均角动量守恒的唯一强迫。 正是这种强迫提供了触发和驱动TC快速强化（RI）的最终机制，这是经典TC强化理论无法解释的。 在目前的业务模式的分辨率，PI表明，次网格尺度（SGS）强迫与对流相关联的边界层以上的TC强化，特别是RI构成了重要的轴承。 如何产生一个现实的SGS强迫高空在TC内核区域是一个新的挑战，湍流混合参数化，以前没有探索。 这个EAGER项目的最重要的特点是：（1）加深我们对与眼壁和雨带对流相关的涡动强迫在调制热带气旋强度变化中的作用的理解;（2）发展物理上可靠的参数化来代表亚热带气旋，在用于TC预测的数值模式中与PBL以上对流相关的网格尺度强迫。该奖项反映了NSF的法定使命，并被认为是值得的。通过使用基金会的知识价值和更广泛的影响审查标准进行评估来提供支持。

The research seeks to advance our understanding of internal dynamics in governing Tropical Cyclone (TC) intensification and improve forecasting skills for rapid change of TC intensity. The results and products of this project can be immediately implemented in operational models for TC prediction, disseminated to the broader TC modeling community, and used in Principal Investigator (PI)'s course teaching in TC theories and applications. The project supports a postdoctoral researcher. The educational goal of the project is to train and educate the next generation of scientists with the engagement of postdoctoral researcher and graduate/undergraduate students.The conventional view of Tropical Cyclone (TC) intensification regards the absolute angular momentum as a materially conserved quantity above the friction layer. This study seeks to demonstrate that the eddy process associated with eyewall and rainband convection serves as a sole forcing for the azimuthal-mean angular momentum conservation. It is this forcing that provides an ultimate mechanism for triggering and driving Rapid Intensification (RI) of TCs that cannot be explained by the classic TC intensification theories. At the current resolution of operational models, the PIs demonstrate that the sub-grid scale (SGS) forcing above the PBL associated with convection poses an important bearing on TC intensification, especially RI. How to generate a realistic SGS forcing aloft in the TC inner-core region is a new challenge in turbulent mixing parameterization that has not been previously explored. The most important features of this EAGER project are: (1) advance our understanding of the role of eddy forcing associated with eyewall and rainband convection in modulating intensity change of TCs and (2) develop physically robust parameterization to represent sub-grid scale forcing associated with convection above the PBL in numerical models used for TC prediction.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.